High temperature metal and intermetallic matrix composite rotating ring structures reinforced with ceramic fibers are known in the prior art. However, methods for making the prior art structures generally suffer from one or more serious disadvantages, making them less than entirely suitable for their intended purpose.
The high temperature metal and intermetallic matrices for such composites include titanium base metals, nickel base metals and molybdenum disilicide.
As used herein, the term "titanium base metal" refers to titanium-aluminum intermetallic compounds (hereinafter called titanium aluminides) and other intermetallics and alloys comprising at least one half titanium. The titanium aluminides are intermetallic compounds wherein titanium and aluminum are present in simple numerical ratios, and they include Ti.sub.3 Al, TiAl and TiAl.sub.3. Some known titanium base alloys are Ti-35V-15Cr, Ti-6Al-4V, Ti-14Al-21Nb, Ti-36Al-6Nb-1Ta, Ti-10Al-26 Nb and Ti-6Al-2Sn-4Zr-2Mo (also known as Ti-6242). All of the alloy compositions herein are described with reference to weight percentages of alloying elements.
As used herein, the term "nickel base metal" refers to nickel-aluminum intermetallic compounds (also called nickel aluminides) and high temperature alloys comprising at least one half nickel. The nickel aluminides include NiAl and Ni.sub.3 Al.
Some references disclosing methods of manufacturing titanium base metal composites reinforced with ceramic fibers are Siemers U.S. Pat. No. 4,786,566 and Wright et al U.S. Pat. Nos. 4,867,644 and 4,919,594. Siemers discloses the radio frequency plasma spraying of molten titanium alloy particles onto an array of aligned high strength ceramic filaments. The filaments do not contact solid titanium alloy powder, as in the present invention. Siemers consolidates his fiber reinforced composite structure by hot isostatic pressing.
Wright et al U.S. Pat. Nos. 4,867,644 and 4,919,594 disclose a method of making rotor members for gas turbine engines having a titanium alloy matrix reinforced by ceramic filaments. A unidirectional mat of ceramic filaments is laminated between a pair of elongate metal foils, which are consolidated to form a composite ceramic fiber/metal matrix ribbon. The ribbon is wound spirally around a mandrel, resulting in a hoop form. The hoop form is converted into a unitary body by hot isostatic pressing.
Methods disclosed in the Siemers and Wright et al patents are difficult to control and extremely expensive to implement compared with methods starting with cast powder-ceramic fiber tapes.
Jarmon et al U.S. Pat. No. 4,808,076 claims a rotor for a gas turbine engine made from a glass or glass ceramic matrix reinforced with silicon carbide fibers. The rotor is made by sandwiching alternate layers of unidirectional silicon carbide monofilament mats between layers of glass or glass ceramic powder matrix tape reinforced with discontinuous silicon carbide yarn.
It is a principal objective of the present invention to provide a method of forming high temperature metal and intermetallic matrix composites reinforced with ceramic fibers, utilizing cast tapes having a powdered metal matrix.
An additional objective of the invention is to provide a method of making fiber reinforced composite rings wherein the product has a controlled distribution of fibers in both the radial and axial directions. The fiber distribution is preferably uniform in both directions.
Additional objectives and advantages of the invention will become apparent to persons skilled in the art from the following detailed description.